Purchase Price Consideration of Xelerated (Detail) (Xelerated Ab, USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Xelerated Ab
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Accounts receivable	$ 2,407
Inventory	6,481
Prepaid and other current assets	111
Property and equipment	441
Tangible assets acquired	9,440
Goodwill	22,324
Intangible assets	51,800
Total assets acquired	83,564
Accounts payable	(256)
Accrued liabilities	(7,152)
Deferred tax liability	(1,000)
Net assets acquired	$ 75,156